JP3533804B2 - Exposure equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus for optically processing an object by irradiating the object with light through an exposure mask.

[0002]

2. Description of the Related Art FIG. 8 is a schematic view of a conventional exposure apparatus. In the figure, 41 is a light source, 1 is light, 42 is an exposure mask, 3
Is an object. The light 1 such as the laser light from the light source 41 is
The light passes through the exposure mask 42 and is guided to the object 3 placed therebelow, and optical processing is performed with a pattern according to the exposure mask 42. However, since the in-plane intensity distribution of the light flux of the light 1 is not completely uniform, there is a problem that the processing characteristics of the object 3 become non-uniform depending on the exposure position.

For example, Appl. Phys. Lett.
62 (10), (1993-3-8), P.P. 1035-
As described in 1037, there is a technique of writing a fiber grating in an optical fiber by using a phase grating as the above-mentioned exposure mask.

FIG. 9 is a schematic view of a conventional fiber grating writing apparatus, FIG. 9 (A) is a sectional view, and FIG.
9B is an enlarged view of the diffraction grating processed portion, and FIG. 9C is an enlarged view of the core portion of the optical fiber. In the figure, 51 is ultraviolet light, 5
Reference numeral 2 is a diffraction grating, 52a is a diffraction grating processed portion, 53 is an optical fiber, 53a is a core portion, and 54 is an interference pattern. As shown in FIG. 9A, ultraviolet rays 51 from a light source such as an excimer laser irradiate a diffraction grating 52. Figure 9
As shown in (B), since the diffraction grating processed portion 52a is engraved on the lower surface of the diffraction grating 52, the ultraviolet rays 51 diffract to diffract the 0th order light, the −1st order light, the 1st order light, and the like. Produces light. The diffraction grating a is processed so that the 0th-order light is suppressed.

As shown in FIG. 9C, an optical fiber 53 arranged in contact with or adjacent to the diffraction grating processed portion 52a.
In the core portion 53a of the interference pattern 5 along the longitudinal direction.
4 appears. The core portion 53a is germanium-doped, and its refractive index increases when it receives the ultraviolet rays 51.
As a result, it is possible to manufacture a fiber grating whose refractive index changes periodically according to the interference pattern of the ultraviolet rays 51.

In such a fiber grating writing apparatus, since the in-plane intensity distribution of the light flux of the ultraviolet rays 51 is not completely uniform, there is a problem that a highly uniform grating spectrum cannot be obtained.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and provides an exposure apparatus in which the processing characteristics of an object to be optically processed are substantially uniform without depending on the exposure position. It is intended to be provided.

[0008]

According to a first aspect of the present invention, there is provided an exposure apparatus which irradiates an object with light through an exposure mask to optically process the object. In an exposure apparatus characterized in that at least one of the objects is relatively moved, a compensation optical path is provided, and the compensation optical path is at least a part of light that has left the object due to relative movement of the light and the object. It is characterized by irradiating an object by guiding the beam.

According to a second aspect of the present invention, in the exposure apparatus according to the first aspect, the compensating optical path includes a secondary mirror and an auxiliary mirror that relatively move in accordance with the relative movement. is there.

According to a third aspect of the present invention, in the exposure apparatus according to the first or second aspect, the exposure mask is a phase grating, the light is ultraviolet light, and the object is an optical fiber. It is a feature.

[0011]

[0012]

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a first exposure apparatus according to the present invention.
1A and 1B are explanatory diagrams of the embodiment of FIG.
(B) and FIG. 1 (C) are explanatory diagrams showing the three relative positional relationships between the light and the object. In the figure, the same parts as those in FIG. 2 is a primary mirror. The object 3 shown in the figure shows only the range to be exposed, and the exposure mask 42 of FIG. 8 covering the object 3 is omitted. The light from the light source and the object 3 are denoted by reference signs a to d.
Shows the correspondence with the light received by. In this embodiment, the light 1 is scanned on the object 3 by moving at least one of the light 1 and the object 3 relatively left and right.

In FIG. 1B, the light 1 from the light source is
The light enters the main mirror 2 horizontally from the left, reflects vertically downward, and enters the object 3. In this example, the left and right lengths of the object 3 are set to the light 1
Therefore, only half of the light flux of the light 1 is incident on the object 3. The remaining light flux leaves the object 3. Based on this positional relationship, the object 3 is moved left and right with respect to the light 1 or the primary mirror 2.

FIG. 1 (A) shows a state where the left end of the object 3 has moved to the left boundary of the light beam, and FIG. 1 (C) similarly moves the right end of the object 3 to the right boundary of the light beam. It is the state when it was done. The movement of the object 3 causes light 1 to travel on the object 3.
Are scanned. As a result, even if the in-plane intensity of the luminous flux of the light 1 is non-uniform, at the end of the exposure time, each part on the object 3 is substantially uniformly irradiated with the light 1, so that the irradiation energy is uniform. Can be realized. Although the object 3 side is moved, the light 1 or the primary mirror 2 side may be moved to scan the light 1 as long as the both move relatively. The movement to the left and right may be one round trip, but can also be repeated periodically.

If the length of the object 3 to be exposed is shorter than the width of the light beam of the light 1, each part of the object 3 always receives the light 1 while keeping the object 3 within the maximum range of the width of the light beam. As a limit, it can be largely moved to the left and right, and the light received by each part on the object 3 is made uniform in a short exposure time. Also, if the moving range is made longer, the exposure time will be longer,
It can be made more uniform.

When moving to the left and right, a state in which a part of the light 1 is deviated from the object 3 occurs, but at the end of the exposure time, the moving range and movement are such that the irradiation time of each part on the object 3 becomes substantially equal. It is possible to set the speed. For example, until the left end of the object 3 reaches the right boundary opposite to the width of the luminous flux,
Further, if the right end of the object 3 is moved at a constant speed until it reaches the left boundary on the opposite side of the width of the light flux, the irradiation time of each part on the object 3 becomes equal. Of course, there is no problem as long as the uneven irradiation time is practically acceptable.

As described above, the lateral length, the moving speed, the moving range, etc. of the object 3 can be arbitrarily determined. However, in any case, since the light 1 is allowed to be partly deviated from the object 3, the utilization efficiency of the irradiation energy of the light 1 cannot be said to be sufficient.

Even when the length of the object 3 to be exposed is longer than the width of the light flux of the light 1, the irradiation energy can be made uniform by the relative movement. In this case, when the object 3 is relatively moved beyond the left and right range, the irradiation energy can be made uniform even in the vicinity of the left and right ends of the object 3.

FIG. 2 is an explanatory view of the second embodiment of the exposure apparatus of the present invention, which is shown in FIG. 2 (A), FIG. 2 (B) and FIG.
(C) is an explanatory view showing three relative positional relationships between light and an object. In the figure, the same parts as those in FIG. 8 and FIG. 11, 12 are secondary mirrors, 13,
Reference numeral 14 is an auxiliary mirror. In this embodiment, not only the irradiation energy is made uniform by the relative movement of the light 1 and the object 3, but also the light 1 that has deviated from the object 3 at the time of the relative movement is reflected by the secondary mirrors 11 and 12 and the auxiliary mirror. Object 3 using 13 and 14
Return to the top and use irradiation energy efficiently,
The exposure time can be shortened.

In FIG. 2A, the secondary mirrors 11 and 12 are
The light fluxes of the light 1 reflected by the main mirror 2 are sandwiched at intervals equal to the light flux width, and are arranged so as to face downward at a predetermined angle θ with respect to the horizontal direction. The primary mirror 2 and the secondary mirrors 11 and 12 are fixed in a state where their mutual positional relationship is maintained, and form a first optical system block. On the other hand, object 3
Are placed horizontally so that a length equal to the luminous flux width of the light 1 reflected by the primary mirror 2 is exposed. The auxiliary mirrors 13 and 14 are arranged at intervals equal to the width of the object 3 and are arranged facing upward with a predetermined angle θ with respect to the horizontal direction, and are arranged symmetrically with respect to the secondary mirrors 11 and 12. To be done. The object 3 and the auxiliary mirrors 13 and 14 move while maintaining their mutual positional relationship, and form a second optical system block.

In FIG. 2A, the light 1 is the primary mirror 2
Irradiates the object 3 vertically by the
At least one of the first optical system and the second optical system is relatively moved based on this positional relationship to perform optical scanning to make irradiation energy uniform. At this time, a part of the light, which is deviated from the object 3 due to the relative movement, is guided to the secondary mirrors 11 and 12 by the auxiliary mirrors 13 and 14 and is again irradiated to the object 3.

As shown in FIG. 2B, when the second optical system block is moved in the lower left direction at an angle θ with respect to the first optical system block, the light 1 is scanned to the right. Become. The light in the area cd shown in the drawing, which has deviated from the target object 3, is reflected by the auxiliary mirror 14 and the secondary mirror 11 in that order to become vertical light, and the
The left half of the object 3 that is no longer directly irradiated by is irradiated.

As shown in FIG. 2C, when the second optical system block is moved in the lower right direction at an angle θ with respect to the first optical system block, the light 1 is scanned to the left. become. The light in the area ab shown in the figure, which is deviated from the object 3, is reflected in the order of the auxiliary mirror 13 and the secondary mirror 12 to become vertical light, and illuminates the right half of the object 3 which is no longer directly irradiated by the primary mirror 2.

Even if it is moved in the horizontal direction, if the above-mentioned angle θ is small, the entire area of the object 3 can receive the light 1 almost all the time. Further, even if only one of the secondary mirror and the primary mirror, for example, the auxiliary mirror 14 and the secondary mirror 11 are used and they are lengthened, the secondary mirror and the primary mirror can be largely moved to the left on one side from the reference position in FIG. The object 3 can be optically scanned. In the above description, the light flux widths of the object 3 and the light 1 are equal, but in the arrangement of FIG. 2, only the length of the object 3 is shortened, or only the light flux width of the light 1 is shortened. Further, only the both may be changed to a shorter arrangement.

Further, in FIG. 2A, the auxiliary mirrors 13,
14 and the auxiliary mirrors 11 and 12 are spaced by d, and the auxiliary mirrors 13 and 14 are
When L is a distance of L and is inclined by θ with respect to the horizontal, when at least one of the first optical system block and the second optical system block is relatively horizontally moved when the relationship of tan2θ = L / d is satisfied. By carrying out the optical scanning, the irradiation energy can be efficiently used without light leakage.

FIG. 3 is an explanatory view of the third embodiment of the present invention. FIGS. 3 (A), 3 (B) and 3 (C) show three relative positions of light and an object. It is explanatory drawing which shows a positional relationship.
In the figure, the same parts as those in FIG. 8 and FIG. Reference numerals 21 and 22 are secondary mirrors, and 23 to 26 are auxiliary mirrors. Also in this embodiment, similarly to the second embodiment described with reference to FIG. 2, the irradiation energy is made uniform by the relative movement of the light 1 and the object 3, and the object is moved during the relative movement. The light 1 out of 3 is returned onto the object 3 using the secondary mirrors 21 and 22 and the auxiliary mirrors 23 to 26, and the irradiation energy is used efficiently.

In FIG. 3A, the secondary mirrors 21 and 22 are
The lower end of each of the secondary mirrors 21 and 22 is arranged inwardly at an interval equal to the width of the light flux, which is sandwiched by the light fluxes reflected by the primary mirror 2, and forms a predetermined angle θ with respect to the horizontal direction. Auxiliary mirrors 23 and 24 are vertically arranged below the vertical direction. Primary mirror 2
The secondary mirrors 21 and 22 and the auxiliary mirrors 23 and 24 are fixed while maintaining their mutual positional relationship, and constitute a first optical system block. On the other hand, the object 3 is placed horizontally so that a length equal to the luminous flux width of the reflected light of the primary mirror 2 is exposed. The auxiliary mirrors 25 and 26 are arranged at intervals equal to the width of the object 3, are arranged outward at an angle of a predetermined angle θ with respect to the horizontal direction, and are arranged parallel to the secondary mirrors 21 and 22. The object 3 and the auxiliary mirrors 25 and 26 move while maintaining their mutual positional relationship, and form a second optical system block.

Based on the positional relationship of FIG. 3 (A),
At least one of the first and second optical systems is relatively moved to perform optical scanning to make irradiation energy uniform. At this time, a part of the light that is deviated from the object 3 due to the relative movement is guided to the secondary mirrors 21 and 22 by the auxiliary mirrors 25, 26, 23, and 24 and is again irradiated on the object 3.

As shown in FIG. 3B, the second optical system block is formed at an angle of 90 ° with respect to the first optical system block.
When it is moved to the lower left by 2θ, the light 1 is scanned to the right. The light in the area cd shown in the figure, which is deviated from the object 3, is reflected by the auxiliary mirror 26, the auxiliary mirror 24, and the secondary mirror 21 in this order to become vertical light, and the left half of the object 3 that is not directly irradiated by the primary mirror 2. Irradiate.

As shown in FIG. 3C, the second optical system block is set at an angle of 90 ° with respect to the first optical system block.
When the light is moved in the lower right direction by 2θ, the light 1 is scanned to the left. The light in the area ab in the figure, which is deviated from the target object 3, is reflected in the order of the auxiliary mirror 25, the auxiliary mirror 23, and the secondary mirror 22 to become vertical light, which is not directly irradiated by the primary mirror 2.
Illuminate the right half of.

Even if it is moved in the horizontal direction, if the angle 90 ° -2θ is small, the entire area on the object 3 can receive the light 1 almost all the time. Further, only one of the auxiliary mirrors and the secondary mirror, for example, the auxiliary mirrors 26 and 24 and the secondary mirror 21, is used, and these are lengthened so as to be largely moved from the reference position in FIG. 3A to the left on one side. However, the object 3 can be optically scanned.

In FIG. 3A, the secondary mirrors 21 and 22 are
The light flux of the light 1 reflected by the main mirror 2 is sandwiched with an interval equal to the light flux, and is arranged downward at a predetermined angle θ with respect to the horizontal direction. The primary mirror 2 and the secondary mirrors 21, 22 are fixed while maintaining their mutual positional relationship, and constitute a first optical system block. On the other hand, the object 3 is placed horizontally so that a length equal to the luminous flux width of the reflected light of the primary mirror 2 is exposed. The auxiliary mirrors 25 and 26 are arranged at intervals equal to the width of the object 3, are arranged outward at an angle of a predetermined angle θ with respect to the horizontal direction, and are arranged parallel to the secondary mirrors 21 and 22. Further, the auxiliary mirrors 23 and 24 are vertically arranged above the auxiliary mirrors 25 and 26. Object 3 and auxiliary mirrors 23, 24, 25,
Reference numeral 26 moves while maintaining a mutual positional relationship to form a second optical system block. In each optical system, the distance between the auxiliary mirror 21 and the auxiliary mirror 25, the distance between the auxiliary mirror 22 and the auxiliary mirror 26 is d,
When the distance between the light flux is L, the distance between the light flux and the auxiliary mirror 23 is x, and the distance between the light flux and the auxiliary mirror 24 is x, when the relationship of tan2θ = (2x + L) / d is satisfied, the first optical system block or the second optical system Irradiation energy can be efficiently used by moving at least one of the blocks relatively horizontally to perform optical scanning.

FIG. 4 is an explanatory view of the fourth embodiment of the present invention, and FIGS. 4 (A) and 4 (B) are explanatory views showing two relative positional relationships between light and an object. Is. In the figure, FIG.
The same parts as those in FIG. Reference numerals 31 and 32 are secondary mirrors, and 33 to 38 are auxiliary mirrors. Also in this embodiment, similarly to the second and third embodiments described with reference to FIGS. 2 and 3, the irradiation energy is made uniform by the relative movement of the light 1 and the object 3. ,
The light 1 that has deviated from the object 3 during relative movement is reflected by the secondary mirrors 31, 32.
Also, the irradiation energy is efficiently used by returning the object 3 onto the object 3 using the auxiliary mirrors 33 to 38.

In FIG. 4A, the secondary mirrors 31, 32 are
The light flux of the light 1 reflected by the main mirror 2 is sandwiched, and the light flux is arranged at an interval equal to the light flux width, and is arranged downward at an angle of 45 ° with respect to the horizontal direction. Auxiliary mirrors 33 and 34 are disposed on the left and right sides of the secondary mirrors 31 and 32 in a downward inward direction at an angle of 45 °. Auxiliary mirrors 35 and 3 are provided vertically below the auxiliary mirrors 33 and 34.
6 are arranged inwardly upward at an angle of 45 °. on the other hand,
The object 3 is placed horizontally so that a length equal to the luminous flux width of the light 1 reflected by the primary mirror 2 is exposed. Auxiliary mirror 37,3
8 is disposed vertically below the object 3 and is oriented upward inward at an angle of 45 °, so that the upper end of the auxiliary mirror 37 and the lower end of the auxiliary mirror 38 have the same vertical height. Will be placed. The auxiliary mirror 37 is arranged symmetrically with the auxiliary mirror 36, and the auxiliary mirror 38 is arranged symmetrically with the auxiliary mirror 35.

In this embodiment, the primary mirror 2 and secondary mirror 3
1, 32 and auxiliary mirrors 33 to 38 are fixed in a state where their mutual positional relationship is maintained, and form a first optical system block.
On the other hand, only the object 3 constitutes the second optical system block,
It moves relative to the first optical system in the left-right direction.

Based on the positional relationship of FIG. 4 (A),
At least one of the first optical system and the second optical system is relatively moved to perform optical scanning to make irradiation energy uniform. At this time, a part of the light that is removed from the object 3 by the relative movement is guided to the auxiliary mirrors 33 to 36 and the secondary mirrors 31 and 32 by the auxiliary mirrors 37 and 38, and is again irradiated to the object 3.

As shown in FIG. 4B, when the second optical system block is moved leftward with respect to the first optical system block, the light 1 is scanned rightward. Object 3
The light in the area cd shown in the figure, which is deviated from the above, is reflected in the order of the auxiliary mirror 38, the auxiliary mirror 35, the auxiliary mirror 33, and the secondary mirror 31 to become vertical light, and the left side of the object 3 that is not directly irradiated by the primary mirror 2. Irradiate half.

Although not shown, when the second optical system block is moved to the right with respect to the first optical system block, the light 1 is scanned to the left. The light in the area ab shown in the figure, which is off the object 3, is reflected by the auxiliary mirror 37, the auxiliary mirror 36,
The auxiliary mirror 34 and the secondary mirror 32 are sequentially reflected to become vertical light, and the right half of the object 3 which is not directly irradiated by the primary mirror 2 is irradiated.

In this embodiment, by simply moving the object 3 to the left or right, the light in the area deviated from the object 3 irradiates the area on the object 3 which is no longer directly irradiated by the primary mirror 2. Will be done. As in FIGS. 2 and 3, only one of the auxiliary mirror and the auxiliary mirror, for example, the auxiliary mirror 38, the auxiliary mirrors 35 and 33, and the auxiliary mirror 31 are used, and these are lengthened to obtain the reference position in FIG. Even if it is moved to the left on the one side, the object 3 can be optically scanned.

FIG. 5 is an explanatory view of the fifth embodiment of the present invention, and FIGS. 5 (A) and 5 (B) are explanatory views showing two relative positional relationships between light and an object. Is. In the figure, FIG.
The same parts as those in FIGS. 1 and 4 are designated by the same reference numerals and the description thereof will be omitted. The primary mirror 2 and the secondary mirrors 31 and 32 form a first optical system block, and the object 3 and the auxiliary mirrors 33 to 38 form a second optical system block. At least one of the two optical systems is relatively moved to perform optical scanning to make irradiation energy uniform. Further, the light leaked by the scanning is reflected by the auxiliary mirrors 33 to 38 and the secondary mirrors 31 and 32 and is irradiated onto the mask again, so that the light can be efficiently used.

In FIG. 5A, the secondary mirrors 31 and 32 are
The light flux of the light 1 reflected by the main mirror 2 is sandwiched, and the light flux is arranged at an interval equal to the light flux width, and is arranged downward at an angle of 45 ° with respect to the horizontal direction. Auxiliary mirrors 33 and 34 are disposed on the left and right sides of the secondary mirrors 31 and 32 in a downward inward direction at an angle of 45 °. Auxiliary mirrors 35 and 3 are provided vertically below the auxiliary mirrors 33 and 34.
6 are arranged inwardly upward at an angle of 45 °. on the other hand,
The object 3 is placed horizontally so that a length equal to the luminous flux width of the light 1 reflected by the primary mirror 2 is exposed. Auxiliary mirror 37,3
8 is disposed vertically below the left and right ends of the object 3 and is disposed upward inward at an angle of 45 °, and is vertically below the secondary mirrors 31, 32, but the lower end of the auxiliary mirror 37 is an auxiliary mirror. The upper end of 38 and the height in the vertical direction are equal to each other.
The auxiliary mirror 37 is arranged symmetrically with the auxiliary mirror 36, and the auxiliary mirror 38 is arranged symmetrically with the auxiliary mirror 35.

As shown in FIG. 5B, when the first optical system block is moved leftward with respect to the second optical system block, the light 1 is scanned leftward. Object 3
The light in the area ab shown in the figure, which is deviated from the above, is reflected by the auxiliary mirror 37, the auxiliary mirror 36, the auxiliary mirror 34, and the secondary mirror 32 in this order to become vertical light, and to the right of the object 3 that is not directly irradiated by the primary mirror 2. Irradiate half.

Here, an example in which the second embodiment described with reference to FIG. 2 is used in a fiber grating writing device almost similar to that of FIG. 9 will be specifically described. In FIG. 2, an ultraviolet laser device is used as a light source, the beam diameter of the light 1 and the length of the object 3 are 19 mm, θ is 15 °, and the distance between the auxiliary mirrors 13 and 14 and the secondary mirrors 11 and 32 is 32 mm.
And The object 3 is the optical fiber 53 of FIG. 9 having an exposure mask, and as the exposure mask, the phase grating 5 of FIG.
Instead of 2, a chirp phase grating in which the grating pitch was continuously changed was used.

With this apparatus, a chirped fiber grating in which the Bragg wavelength continuously changes in the longitudinal direction of the optical fiber 53 was prepared. The beam of light 1 emitted from the ultraviolet laser device is applied to the chirp phase grating on the object 3 by the main mirror 2. Primary mirror 2 and secondary mirror 1
1, 12 were reciprocated ± 10 mm to the left and right with respect to the object 3.

FIG. 6 is a spectrum characteristic diagram for explaining the characteristic of the fiber grating written by using the second embodiment of FIG. Further, FIG. 7 is a comparative example,
It is a spectrum characteristic figure of the fiber grating written using the conventional device. The spectral characteristics of the chirped fiber grating correspond to the magnitude of the refractive index modulation in the longitudinal direction of the optical fiber. Compared to the characteristics shown in FIG. 7 in the case where relative movement is not performed, the spectral characteristics shown in FIG. With the characteristics of, a highly uniform grating spectrum was obtained.

That is, in FIG. 7, there is a variation over the entire wavelength region that has dropped to around -40 dB, and in particular, there is observed a portion that drops sharply to around -60 dB near the boundary of the wavelength region. On the other hand, the data written using the embodiment of the present invention is −40 as shown in FIG.
The characteristics were smooth over the entire wavelength range lowered to near dB, and no sharply lowered portion was observed near the boundary of the wavelength range.

[0048]

As is apparent from the above description, according to the invention described in claim 1, since at least one of the light and the object is moved relatively, the in-plane intensity of the light beam of the light 1 is uneven. However, at the end of the exposure time, each part on the target object is irradiated with light almost uniformly, so that the irradiation energy can be made uniform. Further, it has a compensating optical path, and this compensating optical path guides at least a part of the light that has deviated from the object by the relative movement of the light and the object, and irradiates the object with the compensating optical path. There is an effect that the exposure time can be shortened by returning to the object and using irradiation energy efficiently.

According to the second aspect of the invention, the compensating optical path has the auxiliary mirror and the auxiliary mirror that relatively move in accordance with the relative movement, so that the compensating optical path can be constructed with a simple structure. There is.

According to the third aspect of the invention, since the exposure mask is a phase grating, the light is ultraviolet rays, and the object is an optical fiber, it is possible to write a fiber grating on the optical fiber. There is.

[0051]

[0052]

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a first embodiment of an exposure apparatus of the present invention.

FIG. 2 is an explanatory diagram of a second embodiment of the exposure apparatus of the present invention.

FIG. 3 is an explanatory diagram of a third embodiment of the present invention.

FIG. 4 is an explanatory diagram of a fourth embodiment of the present invention.

FIG. 5 is an explanatory diagram of a fifth embodiment of the present invention.

FIG. 6 is a spectrum characteristic diagram illustrating the characteristics of the fiber grating written by using the first embodiment of FIG.

FIG. 7 is a spectrum characteristic diagram of a fiber grating written by using a conventional device.

FIG. 8 is a schematic diagram of a conventional exposure apparatus.

9A and 9B are schematic views of a conventional fiber grating writing device, FIG. 9A is a sectional view, FIG. 9B is an enlarged view of a processed portion of a diffraction grating, and FIG. 9C is a core portion of an optical fiber. FIG.

[Explanation of symbols]

1 ... Light, 2 ... Primary mirror, 3 ... Object, 11, 12, 21-2
2, 31-32 ... Secondary mirror, 13, 14, 23-26, 33
-38 ... Auxiliary mirror, 41 ... Light source, 42 ... Exposure mask, 51
... ultraviolet rays, 52 ... diffraction grating, 52a ... diffraction grating processed portion,
53 ... Optical fiber, 53a ... Core part, 54 ... Interference pattern.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masa Enomoto 1 Taya-cho, Sakae-ku, Yokohama-shi, Kanagawa Sumitomo Electric Industries, Ltd. Yokohama Works (56) Reference JP-A-5-120993 (JP, A) 59-99436 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03F 7/20

Claims (3)

(57) [Claims] 1. An exposure apparatus which irradiates an object with light through an exposure mask to optically process the object,
In an exposure apparatus characterized in that at least one of the light and the object is relatively moved, having an optical compensation path,
An exposure apparatus, wherein the compensation optical path guides at least a part of the light that has left the object by the relative movement of the light and the object to irradiate the object. 2. The exposure apparatus according to claim 1, wherein the compensation optical path includes a secondary mirror and an auxiliary mirror that relatively move in accordance with the relative movement. 3. The exposure apparatus according to claim 1, wherein the exposure mask is a phase grating, the light is ultraviolet light, and the object is an optical fiber.